I am considering purchasing a machine with a 10-15 hp motor (not sure yet). I only have single phase power in my shop. Can I run this large of a motor with a VFD? IF not then what would be the limitations of using a heavy duty static phase converter. I have a 20 hp digital converter running my haas mill but don't really want to pay that much for running a manual machine. I do already have a small VFD on my Lagun manual mill (read bridgeport) and love the thing on there. I have a source that may have some used vfds in the 20-30hp range but don't imagine they will like running on single phase input.

JP

Is the machine with the 10-15hp running a 3ph motor straight off the line or does it have a Spindle controller?
If the former, then You might get away with a VFD set for 60hz only, with slow ramp up.
You may be restricted to operating in lighter duty.
That is if the VFD does not require or monitor the 3rd phase.
The alternative is a RPC, especially if the machine has a spindle controller.
Al.

From what I currently know the lathe more than likely has the 10 hp motor being run straight off the line by a standard contactor.

So my choices are RPC or Digital PC not a Static PC? I really don't want to spend the money it would require for a RPC or Digital but I suppose if those are my options. I might just tap into my 20hp digital running my Haas except that then I could only run one or the other. Maybe that will have to work until I have some money saved up to buy a second Digital.

JP

If it is currently being run straight off the line, and your motor is 230V or can be reconnected for 230V, then you can use a 230V VFD for 1 phase input, just make sure the VFD is twice as big as the motor; in your case buy a 20HP drive. The problem Al mentioned about monitoring or needing the 3rd phase is common on 480V VFDs, but not too much on 240V versions because it is very common to run 240V from a 1 phase source.